Some of the most popular garments today have a stone-washed appearance. Stone-washing is intended to give a garment at the time of purchase the look and feel normally achieved through repeated washings. Stone-washing, which involves tumbling wet garments with pumice stones to give the desired appearance and feel, has drawbacks including:
1. Pumice stones impart abrasion and impact upon the garments being treated. A heavier thread, therefore, is required, increasing the garment unit cost, while at the same time reducing the stitch rate in the sewing process and substantially reducing productivity.
2. Damage is caused to the seams and hems of stone-washed garments even though heavier thread is used; 15% or more of stone-washed garments have to be reworked at substantial cost. A significant number of the reworked garments are damaged to the extent that they must be downgraded in value and sold as seconds (irregulars).
3. Pumice stones are expensive; they break down and have to be replaced after only a few uses. The sand resulting from the breakdown of the pumice stones constitutes a substantial clean-up and disposal problem.
4. Pumice stones by their nature are highly abrasive, causing excessive equipment wear. Existing process drums are often replaced on an annual or biennial basis.
5. Stone-washing is extremely labor intensive as each garment has to be manually handled to remove pumice stone and sand from all pockets, sleeves, pant legs, etc.